I have a 93 6pd cammed lt1. I have sprayed 150 on it for 8 years without a problem. It has a 255lph in tank pump. I am installing AI 190s, and expect around 400rwhp. My wet kit robs the rail for fuel, it has been fine in the past, but I'm not sure if after the heads, should have a dedicated fuel system. Anyone in the same boat? I would prefer to keep it simple, and not add a seperate system. However, obviously, if I'm near melting it down I will do whatever to save it. Thanks

 

how about a double pump setup?

 

Might want to scan through the stickies on the "Fuel and Ignition" forum.

 

A walbro 255lph (GSS340) will support 530 rwhp for forced induction, maybe a bit more for nitrous. It might be wise to invest in a fuel pressure gauge and definitely wideband for monitoring AFR.

 

Call Nitrous Outlet and ask. They explained to me that a racetronix 255 kit with a hotwire can support 600rwhp maybe more.

-Dustin-

 

Just keep in mind that the fuel demand is calculated based on the flywheel HP, not rear wheel HP. When I switched from the T56 to the TH400 (21.3% drivetrain loss), my rwHP dropped by 70HP (700 to 630), but the fuel consumption didn't change a bit, because the engine was still making 800HP at the flywheel.

The typical online sizing routines recommend a BSFC of 0.50 #/HR/HP for NA applications, 0.55 for nitrous and S/C applications, and 0.60 for turbo applications. If you want to compare fuel demand on a flywheel HP basis, compare a nitrous application to a S/C'd application.

I make 500HP at the flywheel on a single 205LPH Bosch high pressure pump. With the 300-shot, I add a second 205LPH pump. All the fuel, for 800HP flows through a -6AN line, which is roughly the same size as the stock 3/8" supply line. But I'm spraying dry, so all the fuel goes through the rails/injectors. My only concession was to repipe the rails in parallel, rather than in series, to minimize the pressure differences at the first and last injector.

What I would be concerned about with a wet system that takes the fuel for the nitrous off the equivalent of the Schrader valve would be a brief drop in pressure when the fuel solenoid opens. One way to minimize the reduction of fuel supply due to pressure variations is to run the entire system at a higher pressure. I run 58psi for that reason.

EDITED, thanks to koolaid kid. I'm getting careless in my old age.....

 

Ummm, not to correct you Injuneer, but you might have meant "the stock 3/8" supply line", since -6AN = 3/8". Just so other folk don't get confused.

 

Thanks guys, I appreciate it.

 

I stand corrected.